James w



J. W. EASTON.

PUSIBLE GON P ELECTRIC GENERATORS. o.'36 1,273K Patented Apr. 19, 1-887.

UNITED STATES PATENT OFFICE.

JAMES TV. EASTON, OF NET V YORK, N. Y.

FUSlBLE CONNECTION FOR ARMATURES 0F ELECTRIC GENERATORS.

SPECIFICATION forming part 0! Letters Patent No. 361,273, dated April 19, 1887.

Application filed April 13, 1886.

To all whom it may concern:

Be it known that I, JAMES W. EASTON, a subject of the Queen of Great Britain, residing in the city of New York, in the county and State of New York, have invented certain new and useful Improvements in Fusible Gonnectious for the Armatures of Electric Generators, of which the following is a specification.

The invention relates to the class of devices employed for preventing the armature-coils of electric generators from being injured by being overheated.

It frequently chances that, by reason of a short circuit being formed in a generator, an undue amount of current is caused to traverse certain armature-coils, and such currents result in an overheating of the bobbins and destroy theinsulation.

The object of the invention is to provide means for automatically interrupting the circuit-connections through any of the bobbins whenever they areliable to become overheated by reason of a short circuit being formed between any two of the commutator-plates.

The invention consists in connecting each joint between the bobbins with its com mutatorplate through a fusible conductor,which,while normally conveying the currents produced by the generator without developing heat, will be, fused by an excess of current or by reason of currents being transmitted through the same continuously. In the usual forms of dynamoelectric generators the circuit-connections are completed through each contact-plate twice during each revolution of the armature. The fusible conductors are made of such capacity that they willconvey the normal currentsthus generatedwithout becoming heated; but should two of the contact-plates become accidentally connected with each other, then a circuit will be completed through the corresponding fusible conductors continuously,and this will cause them to be heated and softened. The metal of which they are composed will then be thrown outward by centrifugal force, and thus the connections with the corresponding bobbin will become severed before any injury can be done to the wire itself by reason of overheating.

It has been proposed to interpose fusible plugs in the circuit of dynamo and magneto machines in such manner that they will en- Serial No. 198,685. (No model.)

tirely interrupt the circuit when fused; but this construction causes the current to entirely cease when the plugs are brought into action, so that the machine must be stopped at once Ior repairs.

By placing the fusible connections betweeneach joint and the corresponding commutatorplate the machine may continue to operate even after one or more of the connections have been severed.

In the accompanying drawings there is illustrated a portion of an armature of the Gramme type, together with the commutator or collector plates and circuit-connections.

Referring to the figures, A A A represent bobbins of the armature,and thejoints of the wire are connected, respectively,with bindingscrews b b If, &c. The contact-plates c 0 0 850., are mounted in the usual manner, and they are connected, respectively, with the points I) Z)" I) by means of fusible strips (1 d (1. These strips may be of lead or any suitable composition metal, such as is ordinarily employed for fusible conductors. They, preferably extend between the binding screws or points I) 1) 12 to which the joints of the armature-coils are attached, and the plates 0 0" c and may be readily replaced.

The conductivity of the strips d d d is such that they will convey the currents normally produced by the generator without injury or without becoming overheated. As these strips are located where they are exposed to the air, it is evident that they may beof somewhat less conductivity than if they were more or less surrounded, as are the conductors of the bob- This would result in injury to the bobbin,causing it to be burned out, were not means provided to prevent itnamely, the fusible strips. These become heated more quickly than the bobbin and operate upon being softened, so that they sever the connections between the plates and the bobbins before injury is done. After any one of the connections has been thus severed the machine may continue to operate,two plates being connected together, and in this manner currents will continue to be produced by the machine,which will serve to supply the system to which it may be applied in amore or less perfect manner until opportunity is offered for stopping and repairing the machine.

I claim as my invention 1. The combination, with the armature of a dynamo-electric generator, of a fusible connec tion between the joints of the armature-coils and the commutator-plates, substantially as described.

JAMES W. EASTON.

Witnesses:

ISRAEL MA'rsoN, CHARLES A. TERRY. 

